Fluid pressure spike suppression device

ABSTRACT

Systems and apparatus for suppressing/controlling pressure spikes in a fluid pipe system are described. In one aspect, an apparatus for controlling pressure spikes in a fluid pipe system includes, for example, a fluid pressure spike suppression pipe (“damper pipe”) portion with multiple openings for connecting to at least two network pipes in a fluid system pipe network. The damper pipe has a diameter that is larger than respective diameters of the network pipes within which fluid pressure spikes are to be suppressed. First and second openings for connecting to the network pipes are respectively positioned at proximal and distal ends of the damper pipe. The first opening in the damper pipe is for fluid ingress into the damper pipe via a first pipe network pipe. The second opening in the damper pipe is for fluid egress out of the damper pipe and into a second network pipe.

BACKGROUND

Sudden opening or closure of a control valve, or tap, can cause apressure surge or spike in plumbing as a result of forcing a fluid inmotion (or, in some conditions, a gas) to stop or change directionsuddenly. This phenomenon is called water or fluid hammer, and it cancause ruptures and leaks in pipes and fittings. Water hammer createspressure waves that travel upstream and downstream of the closed/openedtaps at nearly the speed of sound. There are a number of standardtechniques that attempt to minimize the pressure spikes resulting fromwater hammer. In pipe networks, for example, common techniques toaddress water hammer include use of surge vessels, equilibrium tanks,pressure relief valves, and suction lines around the booster pump. Inresidential and light commercial/industrial applications, an air chamberand water hammer arrestor may be used for water hammer control.

FIG. 1 shows a prior art pipe network that employs an air chamber toaddress undesirable pressure surges associated with water hammer. Asshown in FIG. 1, this is a conventional technique wherein a shortvertical section of pipe is filled with trapped air. In this scenario,when a valve is suddenly closed, the air chamber acts as a shockabsorber. Air in this chamber compresses and cushions the resultingshock. The disadvantage of this conventional technique/device is thatafter time, the air pocket is eventually absorbed into/by the water,which renders the device ineffective. To remedy this limitation, onemust drain water out of the system to recreate the air pocket. Referringto FIG. 2, a prior art arrestor device designed to address water hammerin a pipe network is shown. As shown in FIG. 2, this solution to waterhammer is similar to that of the air chamber of FIG. 1, with theexception that the air pocket in the arrestor is separated and sealedfrom the water by a piston with an “O” ring or diaphragm so that the aircannot be absorbed by water. The air pocket for this type of waterhammer control device is pressurized to a certain limit. Onedisadvantage of this “arrestor” technique/device is that the pressurelevel of the air pocket is typically too high for the device to workproperly for low pressure applications. Another disadvantage of thisdevice is that the moving piston generally makes it noisy. Furthermore,both the air chamber and water hammer arrestor devices have thedisadvantage of being metallic (usually copper); thus, they aresusceptible to corrosion and erosion.

SUMMARY

Systems and apparatus for suppressing/controlling pressure spikes in afluid pipe system are described. In one aspect, an apparatus forcontrolling pressure spikes in a fluid pipe system includes, forexample, a fluid pressure spike suppression pipe (“damper pipe”) portionwith multiple openings for connecting to at least two network pipes in afluid system pipe network. The damper pipe has a diameter that is largerthan respective diameters of the network pipes within which fluidpressure spikes are to be suppressed. First and second openings forconnecting to the network pipes are respectively positioned at proximaland distal ends of the damper pipe. The first opening in the damper pipeis for fluid ingress into the damper pipe via a first pipe network pipe.The second opening in the damper pipe is for fluid egress out of thedamper pipe and into a second network pipe.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a prior art pipe network that employs an air chamber toaddress undesirable pressure surges associated with water hammer.

FIG. 2 shows a prior art water pipe network that employs an arrestordevice to compensate for sudden water pressure surges associated withwater hammer phenomena.

FIGS. 3( a) and 3(b) show exemplary embodiments of novel water/fluidpressure spike suppression pipe portions (“damper pipes”) in respectivepipe networks.

FIG. 4 shows a pipe network that includes a novel fluid hammer damperpipe (e.g., a “fluid pressure spike damper pipe”) with balloonsinstalled in a typical residential or commercial plumbing networkcomprising a main pipe and a control valve, according to one embodiment.

FIGS. 5( a) through 5(d) show a set of exemplary data showing how aplastic embodiment of the fluid pressure spike suppression(“FPSS”)/damper/control pipe of FIG. 3 performs as compared to a largecommercial water hammer arrestor. Specifically:

FIG. 5( a) shows water hammer results following valve closure in thetest environment without using FPSS pipe device 302;

FIG. 5( b) shows water hammer results following valve closure in thetest environment using a standard prior art large water hammer arrestor;

FIG. 5( c) shows exemplary water hammer results following valve closurein the test environment using a plastic embodiment of the FPSS pipe 302of this disclosure without compressible inserts (e.g., balloons filledwith air/gas), according to one embodiment; and

FIG. 5( d) shows exemplary water hammer results following valve closurein the test environment using a FPSS pipe 302 with three balloon inserts306 encapsulating air at a pressure equal to the normal pressure in thefluid pipe network, according to one embodiment.

DETAILED DESCRIPTION An Exemplary Plastic Water Hammer Damper

FIGS. 3( a) and (b), which are collectively referred to hereinafter asFIG. 3, show exemplary embodiments of a fluid pressure spike suppression(“FPSS”)/damper (“FPSD”)/control pipe 302. In this particularimplementation, the novel FPSS device 302 is for suppressing fluid(e.g., water) hammer in residential and commercial fluid systemscomprising plastic and/or metallic pipes—although, in anotherimplementation, the concepts disclosed in this specification can also beused in gas systems, as compared to fluid systems, to dissipate suddengas pressure spikes. In this implementation, the device comprises theFPSS pipe/vessel portion 302 (e.g., made from Polychloroethene or “uPVC”or “PVC”). FPSS 302, which is hereinafter often referred to as a “damperpipe,” has a larger pipe diameter than the connecting pipes 304 (304-1and 304-2) for which pressure spikes in fluids that typically result inwater hammer are to be controlled/suppressed. To this end, and referringto either of FIG. 3( a) or 3(b), first and second network pipe portions304-1 and 304-2 are operatively coupled to the damping pipe 302 in asubstantially perpendicular orientation to the length of the dampingpipe 302. Network pipe 304-1 serves for fluid ingress (an “inlet”) toprovide fluid flow into the damper pipe 302. Please note that as thefluid enters the damper pipe 302 from inlet pipe 304-1, the fluid issubstantially perpendicularly redirected along the length of the damperpipe 302 for egress out the opposite end of the damper pipe 302 vianetwork pipe 304-2 (“outlet”). Please note that in this exemplaryimplementation, the second portion is also perpendicular to theorientation of the damping pipe 302. This network pipe 304 orientationto the damping pipe, which results in fluid flow through the length ofthe damping pipe (ingress at a proximal end 306 and egress at a distalend 308) in normal fluid flow operation, as well as during operation tosuppress a fluid pressure spike, serves to dampen any fluid pressurespike in a substantially optimal manner. In this particularimplementation, fluid ingress or egress at location(s) other than aproximal or distal end (e.g., a centralized location with respect to thelength of the damper pipe) of the damper pipe 302 will not aseffectively mitigate fluid pressure surges in system 300.

Although the diameter of pipe 304-1 may be the same as the diameter ofpipe 304-2, the diameter of a pipe 304 need not be the same and thediameter of a different pipe 304. Additionally, although pipe 304-1 islabeled as an “outlet” and pipe 304-2 is labeled as an “inlet,” theselabels illustrate but one exemplary embodiment of fluid flow direction.Different complementary inlet/outlet (fluid flow) configurations can beused for pipes 304 without departing from the scope of the describedFPSS 302. Damper pipe 302 does not rely on use of any bladder or waterpermeable screen. Moreover, damper pipe 302 is always filled with fluid,meaning that it has different characteristics and does not operate as aconventional air or vacuum chamber to alleviate pressure spikesresulting from fluid hammer. As such, the mechanism (e.g., gas) used inmitigating fluid pressure spikes will not be absorbed over time by thefluid, as in the case of an air chamber.

Referring to FIG. 3( a) and TABLE 1, the following exemplary designparameters of TABLE 1 pertain to but one embodiment of many possibleembodiments of the damper pipe 302. As such, these design parametersoffer preliminary guidelines, but damper pipe 302 can work properly todissipate pressure spikes resulting from water hammer conditions outsidethe parameters of TABLE 1.

TABLE 1 EXEMPLARY FPSS/FPSD PIPE DESIGN PARAMETERS D_(O) > 4D_(n) L_(T)≧ 4D_(O) wherein, D_(O) = damper pipe inside diameter; D_(n) = diameterof the network pipe for which water hammer is to be controlled; andL_(T) = total length for the damper pipe.

In this implementation, the damper pipe (pipe 302) diameter is largeenough so as to expand easily under water pressure. This allows damperpipe 302 to swell in the radial direction; thus it would be able tostore additional fluid resulting from fluid pressure spikes for a timeperiod long enough to allow the pressure spike to travel to the boundaryand to be reflected back with negative pressure spike, resulting in areduction of pressure and relief to the main pipe(s) 304. Thus, thesystem 302 absorbs a fluid pressure spike to quickly restore normalpressure to network pipes 304.

Alternate Embodiments Configurable Balance between Pressure SpikeSuppression Materials and Various Operating Pressure Environments

In one implementation, for example, and to enhance the performance ofthe device 302, a number of air-filled balloon(s) 310 (e.g., balloons310-1 through 310-N) of spherical shape are inserted into the damperpipe 302. Each balloon 310 is comprised of a non-porous plastic orrubber material (not a cellular foam or foam-like material) that isinflated with gas (e.g., air or other gas). Since the gas inside each ofthe one or more balloons 310 is highly elastic, the balloon(s) willshrink when subjected to fluid pressure surge(s) during water hammeroccurrence and expand when fluid pressure is reduced. Because thenon-porous balloons 310 are not foam, the gas in the balloons will notbe absorbed by the substantially continuous presence of liquid in thechamber 302, wherein the presence is independent of fluid pressurespike(s).

In this embodiment, a balloon 310 is inflated with gas (e.g., air) to aselect target and configurable pressure that is based on characteristicsof the selected balloon material and the operating pressure of the pipenetwork 300. In one implementation, for example, the gas pressure insidethese balloon(s) is greater than local atmospheric pressure (absolute)but less than the normal water pressure just upstream of a control valve(e.g., control valve 404 of FIG. 4) plus the additional expectedpressure spike (if no water hammer control is used). Low gas pressureinside the balloons may be suited to low pressure applications. High gaspressure inside the balloons may be suited for high pressureapplications and applications where there may be high fluid pressurespikes, including systems that typically operate at low pressures. Atthe limit, when the gas pressure inside the balloon is equal to the pipenetwork normal pressure plus the expected pressure spike, the balloonitself will not shrink. For this reason, the gas pressure inside theballoons is selected so that it is not low enough to be reducedsignificantly during normal operational conditions and not high enoughto reach levels beyond the maximum pressure levels recommended for thepipe(s).

The following exemplary design parameters shown in TABLE 2 pertain tobut one embodiment of the possible alternate embodiments of theFPSS/FPSD device 302 (please see FIG. 3( a)) comprising one or moreballoons 310 or balloon-like devices, which are referred to collectivelyas “balloon(s).” As such, these design parameters offer preliminaryguidelines, but this alternative embodiment of the damper pipe 302 canwork properly to dissipate pressure spikes resulting from water hammerconditions outside these parameters.

TABLE 2 EXEMPLARY FPSS/FPSD PIPE BALLOON DESIGN PARAMETERS L_(b) <0.8L_(T) D_(b) ≦ 0.9D_(O) P_(atm) ≦ P_(b) ≦ P_(n) + N wherein, D_(b) =Balloon diameter, L_(b) = Summation of balloon diameters, P_(atm) =Local atmospheric pressure (absolute), P_(b) = Air pressure insideballoon (absolute), P_(n) = Normal network pressure just upstream ofcontrol (absolute), and N = Pressure increase at the location of thedamper due to the spike from water hammer if no pressure spikesuppression device is used. The magnitude of this variable is obtainedby subtracting the normal pressure before spike from the maximumpressure level after pressure spike due to fluid transient.

In one implementation, and because different materials havecorresponding elastic or tensile strength properties, respective ones ofthe balloon(s) 310 are comprised of material that is particularlyselected to correspond to target in-balloon gas pressure level(s) torespectively allow or to constrain volume contraction or expansion ofthe respective balloons. This provides for the balloon material(s) to beselectively matched with target internal gas pressures when configuringthe design of the damper device 302 for a particular fluid networkapplication (e.g., high, low, and/or medium pressure application(s)).

Retaining Mesh to Encapsulate Balloon in High Pressure Operations

In one embodiment, and as shown in FIGS. 3( a) and 3(b), one or moreballoons 310 is/are encapsulated in a retaining mesh 312. Such aretaining mesh 312 is shown as a matrix of intersecting lines on aballoon 310. A balloon 310 without the retaining mesh 312 is shown asballoon 310-N in FIG. 3( b)). The retaining mesh 312 maintains a fixedballoon volume even when the gas pressure that has been configuredinside the balloon would otherwise expand the balloon's diameter (i.e.,if the mesh were not there to constrain such expansion). This is incontrast to conventional water hammer suppression systems, whereinpressure in such conventional systems may be limited to a maximum, whichis when the balloon diameter is equal to the inner diameter of the waterhammer suppression chamber.

In one embodiment, the retaining mesh 312 comprises wire and/or othernon-elastic material. A balloon 310 encapsulated in a retaining mesh ishereinafter often referred to as a “caged balloon.” The mesh 312 isconstructed such that it has holes between respective portions of themesh, wherein each hole allows a configurable portion of fluid pressurein the FPSS chamber 302 to influence a configurable portion of thesurface of the balloon for corresponding contraction of the balloon indesired circumstances (e.g., fluid pressure spikes of configurablemagnitude). In one implementation, the size of the holes in theencapsulating mesh is configured based on one or more of: (a) elasticand/or tensile characteristics of the balloon material; (b) normaloperating pressure of the pipe network that includes the FPSS device302; and (c) internal pressure of the gas inside the balloon. Oneexemplary use of one or more caged balloons is in a fluid pipe networkthat operates normally at high pressure and wherein corresponding fluidpressure spikes will be high pressure. In this scenario, and to suppressfluid hammer in such a system, the gas pressure inside the balloon(s)310 is increased to accommodate for corresponding fluid pressure spikesin the system.

In one implementation, low gas pressure in the balloons 310 is used tosuppress fluid hammer in a low pressure system. In this scenario, one ormore caged balloons 310 may or may not be used, as desired, in the samesuppression chamber 302 to address a range of system conditions. Forexample, in one implementation, a combination of non-caged balloons 310and caged balloons 310 are used in a damper pipe 302 that istargeted/installed for/in a low pressure system to address anyoccurrence of a high pressure fluid pressure spike in the system. Inanother example, caged balloons and balloons without cages could be usedin the same chamber 302 so that the caged balloons take care of positivepressure spikes (pressure increases) and balloons without cages takecare of low pressure spikes (negative pressures) by expanding accordingto Boyle's law.

The described implementations of system 300, wherein a retaining mesh312 is used to constrain expansion of a balloon 310, are in contrast toconventional water hammer suppression devices that may not be useful;for example, to address water hammer in high and/or low pressuresystems. This is because, in such standard systems, pressurizing aballoon may cause corresponding balloon volume expansion, andde-pressurizing a balloon may cause corresponding balloon volumecollapse. For instance, a conventional system for water hammersuppression may prescribe use of crushable plastic foam (or cellularplastic) in a pressure vessel to address negative effects of waterhammer. Cellular foam is generally considered to be a substance formedby trapping many gas bubbles in a liquid or solid. In such a standardsystem: (a) the inside pressure of bubbles in cellular foam or othercontainer is generally limited; (b) elasticity of the foam and itsresponse to loading and unloading conditions is generally toopoor/limited to handle surge pressures in pipelines; (c) air bubbles inthe foam will likely dissipate over time responsive to water hammershock (or otherwise be absorbed into the fluid in the system); and (d) aprohibitively large volume of foam may be required to provide a desiredair (bubble) volume.

FIG. 4 shows an exemplary FPSS/FPSD device 302 with balloons 310installed in a typical residential or commercial plumbing networkcomprising a main pipe 402 and a control valve 404, according to oneembodiment.

Plastic Water Hammer Damper

In one implementation, damper pipe 302 is made of plastic. In thisimplementation, there are no corrosion/erosion problems that occur formetallic dampers/arrestors. Since there are no moving parts in thisparticular implementation of damper pipe 302, the device will not resultin noise or bangs, as compared to the noise generally associated with aconventional water hammer arrestor.

Exemplary Performance

An exemplary set of parameters that effect the following are described:(a) pressure spike suppression when using a plastic chamber withoutballoons; and (b) pressure spike suppression when using air-filledballoons inserted in a steel chamber. As described, steel chamberresponse to pressure spike is negligible. Isolating the effect ofchamber enables quantifying the effect of the balloons only.

Plastic Pressure Spike Damper (Plastic Chamber Without Balloons)

The parameters that affect the performance of this device are pipediameter (D), pipe length (L), fluid velocity or discharge (Q), Young'smodulus of elasticity for the damper material (E_(D)), damper length(L_(D)), damper diameter (D_(D)), damper wall thickness (e_(D)),pressure spike in pipe network due to water hammer (when no pressuresurge control device is used) (N), fluid modulus of elasticity (K),Young's modulus of elasticity for the pipe (E), and pipe wall thickness(e). The following equations relate the reduction of pressure spike bythe spike suppression device as a function of these parameters:

$\begin{matrix}{R = {\frac{\Delta \; V_{D}}{\Delta \; V_{D - \max}} = \frac{\left( {N\; \pi \; D_{D}^{3}\frac{L_{D}}{4e_{D}E_{D}}} \right)\sqrt{1 + \frac{K\; D}{E\; e}}}{2840\; Q\; L}}} & (1) \\{\frac{{\Delta \; p_{w\; o}} - {\Delta \; p_{w}}}{\Delta \; p_{w}} = {f(R)}} & (2)\end{matrix}$

wherein ΔV_(D) is the extra volume available due to damper pipeexpansion from pressure spike, ΔV_(D-max) is the fluid volume admittedfor complete water hammer elimination and is equal to the volume offluid that enters the pipe in a time equal to 2Q/a, Δp_(wo) is thepressure spike in the pipe when no damping device is used, and Δp_(w) isthe pressure spike in the pipe when the spike suppression device isused.

Using different values for all the above parameters, more than 80 pointswere investigated. The left hand side of Eq. 2 is multiplied by 100 andplotted against the right hand side of Eq. 2 as shown in TABLE 3. If oneknows the different parameters on the right-hand side of Eq. 2, thatmeans the R value is known and it is possible to estimate the expectedreduction; or, if there is a target reduction of pressure spike, onecould enter the graph and obtain R from which it is possible to decideabout which parameters values could be used to result in the desired Rvalue:

TABLE 3

Air-Filled Balloons Inserted in a Steel Chamber

The parameters that affect the performance of the pressure spikesuppression device are: local atmospheric pressure (p_(atm)), gaspressure inside the balloon (p_(b)), pipe pressure during normal systemoperation (p_(p1)), maximum pressure spike in the pipe if no spikecontrol device is used (p_(p2)), pipe length (L), fluid modulus ofelasticity (K), pipe diameter (D), Young's modulus of elasticity for thepipe (E), pipe wall thickness (e), discharge in the pipe (Q), cagedballoon volume (V₀), and balloon initial pressure (the pressurenecessary to inflate the balloon until it just starts pressing the cage)(p₀). The equations analogous to Eqs. (1) and (2) above are:

$\begin{matrix}\begin{matrix}{R = \frac{\Delta \; V_{D}}{\Delta \; V_{D - \max}}} \\{= \left( \frac{\left( {p_{atm} + p_{b} - p_{0}} \right){V_{0}\left( {\frac{1}{p_{p\; 2} + p_{atm}} - \frac{1}{p_{p\; 1} + p_{atm}}} \right)}\sqrt{1 + \frac{K\; D}{E\; e}}}{2840\; Q\; L} \right)}\end{matrix} & (3) \\{\frac{{\Delta \; p_{wo}} - {\Delta \; p_{w}}}{\Delta \; p_{w}} = {f(R)}} & (4)\end{matrix}$

Ten tests were carried out with a range of values for all the parametersmentioned above. The left-hand side of Eq. 4 is multiplied by 100 andplotted against the right-hand side of Eq. 3 to obtain FIG. 4. With allthe values of the pipe and balloon parameters known, one could estimatethe reduction in pressure spike from TABLE 4; or if it is desired tohave a given target reduction, one could enter the curve from thereduction % axis and read the value of the volume ratio. When this valueis used in Eq. 3, one could decide which parameters take which values toreach this value of volume ratio, as shown in TABLE 4:

TABLE 4

An Exemplary Plastic Water Hammer Damper with Balloons

One could use balloons inside a plastic chamber to obtain theperformance of the device as indicated; for example, in TABLES 3 and 4.For instance, if the desired spike reduction is 80%, one could use 70%of this value for the balloons and the remaining 30% would be for theplastic chamber to absorb. These are target reductions.

FIGS. 5( a) through 5(d) show a set of exemplary data to compareexemplary performance of the disclosed plastic water hammer damper 302with performance of a large commercial water hammer arrestor in asubstantially similar plumbing network. For purposes of exemplarycomparison, a test, the information and results of which are shown inrespective ones of FIGS. 5( a) through 5(d), was carried out in theground floor of a residential building with an elevated storage tankthat supplies water to the building by gravity. In this example, theelevation difference between the control valve and the water level inthe elevated storage tank was about 10-12 m. The water hammer damper 302for this test was having a damper pipe diameter of 101.6 mm and damperpipe length of 750 mm. FIG. 5( a) shows water hammer results followingvalve closure in the test environment without using damper pipe device302. FIG. 5( b) shows water hammer results following valve closure inthe test environment using a commercially available large water hammerarrestor. FIG. 5( c) shows exemplary water hammer results followingvalve closure in the test environment using the plastic water hammerdamper 302 of this configuration without balloons 310, according to oneembodiment. FIG. 5( d) shows exemplary water hammer results followingvalve closure in the test environment using a FPSS 302 with threeballoons 310 with pressure equal to the normal pressure in the network,according to one embodiment. As shown, in FIGS. 5( a) through 5(d), theFPSS 302 provides substantially better reduction of water hammerpressure than the commercial water hammer arrestor (please see FIG. 5(b)). Additionally, use of the FPSS 302 with a set of balloons 310substantially enhances performance of the device 302 to address fluidpressure surges responsive to the water hammer. Please note that fluidpressures responsive to the water hammer were further reduced as thenumber of balloons 310 used in the device 302 is increased.

Although the above sections describe systems and methods for a FPSS 302in language specific to structural features and/or methodologicaloperations or actions, the implementations defined in the appendedclaims are not necessarily limited to the specific features or actionsdescribed. Rather, the specific features and operations for the FPSS 302are disclosed as exemplary forms of implementing the claimed subjectmatter.

1. An apparatus for suppressing a pressure spike in a fluid system, theapparatus comprising: a fluid pressure spike suppression (“FPSS”) pipehaving a plurality of openings for coupling with a plurality of networkpipes in a fluid system, the FPSS pipe having a diameter that is largerthan the network pipes within which fluid pressure spikes are to besuppressed, first and second openings of the openings being respectivelypositioned substantially perpendicular to the FPSS pipe at proximal anddistal ends of the FPSS pipe, the first opening for fluid ingress intothe FPSS pipe by a first pipe of the network pipes, the second openingfor fluid egress from the FPSS pipe via a second pipe of the networkpipes.
 2. The apparatus of claim 1, wherein the FPSS pipe is plastic. 3.The apparatus of claim 1, wherein the FPSS pipe is metal.
 4. Theapparatus of claim 1, wherein D_(O) is an inside diameter of the FPSSpipe, D_(n) is a diameter of a network pipe of the network pipes, L_(T)is a total length of the FPSS pipe, and P_(n) is a normal main trunkline fluid pressure upstream and proximal to a control valve, andwherein:D_(O)>4D_(n)L_(T)≧4D_(O).
 5. The apparatus of claim 1, wherein the FPSS pipe furthercomprises a set of gas-filled balloons that are flexible under fluidpressure spikes pressure N.
 6. The apparatus of claim 5, wherein one ormore of the gas-filled balloons are encapsulated in a retaining mesh,the mesh constraining expansion of the one or more balloons frompressure of gas inside respective ones of the one or more balloons. 7.The apparatus of claim 1, wherein the FPSS pipe further comprises a setof gas-filled balloons that are flexible under fluid pressure spikespressure N, and wherein D_(O) is an inside diameter of the FPSS pipe,D_(n)is a diameter of a network pipe of the network pipes, L_(T) is atotal length of the FPSS pipe, P_(n) is a normal main trunk line fluidpressure (absolute) upstream and proximal to a control valve, D_(b) isdiameter of each of the gas-filled balloons, L_(b) is a summation ofballoon diameters, N is pressure spike due to water hammer if nopressure spike suppresser is used and P_(b) is gas pressure inside eachballoon (absolute), and whereinD_(O)>4D_(n)L_(T)≧4D_(O)L_(b)<0.8L_(T)D_(b)≦0.9D_(O)P _(atm) ≦P _(b) ≦P _(n) +N.
 8. A water pipe system comprising: a trunkline for carrying water; a fluid pressure spike damping (“FPSD”) pipefor mitigating fluid pressure spikes in the water pipe system, the FPSDpipe being operatively coupled via two (2) openings to respective onesof first and second network pipes of the main trunk line, the FPSD pipehaving a diameter that is larger than the first and second networkpipes, the first and second network pipes being respectively coupled viarespective ones of the first and second openings at proximal and distalends of the FPSD pipe, the first network pipe for fluid ingress into theFPSD pipe at an orientation that is substantially perpendicular to alength dimension of the FPSD pipe, the second network pipe for fluidegress from the FPSD pipe into the FPSD pipe at an orientation that issubstantially perpendicular to the length dimension, the lengthdimension being four or more multiples of an inside diameter of the FPSDpipe.
 9. The water pipe system of claim 8, wherein the FPSD pipe isplastic.
 10. The water pipe system of claim 8, wherein the FPSD pipe ismetal.
 11. The water pipe system of claim 8, wherein D_(O) is an insidediameter of the FPSD pipe, D_(n) is a diameter of a network pipe of thenetwork pipes, L_(T) is a total length of the FPSD pipe, and P_(n) is anormal main trunk line fluid pressure (absolute) upstream and proximalto a control valve, and whereinD_(O)>4D_(n)L_(T)≧4D_(O).
 12. The water pipe system of claim 8, wherein the FPSDpipe further comprises a set of gas-filled balloons that are flexibleunder fluid pressure spikes pressure N.
 13. The water pipe system ofclaim 12, wherein one or more of the gas-filled balloons areencapsulated in a retaining mesh, the mesh constraining expansion of theone or more balloons from pressure of gas inside respective ones of theone or more balloons.
 14. The water pipe system of claim 8, wherein theFPSD pipe further comprises a set of gas-filled balloons that areflexible under fluid pressure spikes pressure N, and wherein D_(O) is aninside diameter of the FPSD pipe, D_(n) is a diameter of a network pipeof the network pipes, L_(T) is a total length of the FPSD pipe, P_(n) isa normal main trunk line fluid pressure (absolute) upstream and proximalto a control valve, D_(b) is diameter of each of the gas-filledballoons, L_(b) is a summation of balloon diameters, Nis pressure spikedue to water hammer if no pressure spike suppresser is used and P_(b) isgas pressure inside each balloon (absolute), and whereinD_(O)>4D_(n)L_(T)≧4D_(O)L_(b)<0.8L_(T)D_(b)≦0.9D_(O)P _(atm) ≦P _(b) ≦P _(n) +N.